Salil Tiwari
Embedded Systems Engineer
3+ years specializing in ARM Cortex-M4 microcontrollers, RTOS multitasking, and high-reliability PCB design.
Core Competencies
Firmware & RTOS
Multitasking logic, low-level driver architecture, and optimization.
Hardware & PCB
Multi-layer routing, EMI minimization, and component footprints.
Protocols & Lab Work
Industrial bus integration and physical hardware debugging.
Engineering Practice & Collaboration
Problem Solving & Debugging
Root-cause analysis for complex hardware-software bugs and system latency.
Cross-Functional Collaboration
Partnering with quality, calibration, and assembly teams for production yield.
Workflow & Documentation
Process automation, technical reporting, and knowledge transfer across SMEs.
Featured Engineering Projects
RTOS Display & UI Firmware
Smart Meter TOU & Power Demand
- Optimized RTOS task execution and interrupt routines to completely eliminate UI button latency.
- Engineered a fully configurable GUI menu system with high-resolution display firmware in C and FreeRTOS.
- Created custom Modbus registers for real-time data exchange, telemetry monitoring, and remote configuration.
- Developed active power demand and Time-of-Use (TOU) energy calculation algorithms for Peak, Sharp, Valley, and Normal tariff bands.
- Built robust automatic data recovery mechanisms in non-volatile memory to prevent information loss during power outages.
- Implemented a TOU chart engine supporting over 100 user-configurable parameters with integrated automatic error checking and correction suggestions.
Designed time-of-use and average power demand graph rendering on ARM Cortex-M4 smart meters deployed in the German industrial market.
USB Flash-Drive Form Factor
USB to RS232 Galvanic Isolated Converter
- Achieved reliable 115.2 Kbps data speeds with 2.5kV galvanic isolation using high-performance digital isolators and isolated DC-DC converters.
- Protected connected laptops and host USB controllers from severe industrial ground loops, high-voltage spikes, and transient surges.
- Enforced strict 4mm isolation gap creepage and clearance rules across the isolation barrier to maintain safety and compliance standards.
- Utilized dedicated internal ground and power planes to minimize electromagnetic interference (EMI) and maintain clear signal integrity.
- Executed thorough DFM and DRC analysis in Altium to guarantee high manufacturing yield and long-term hardware field reliability.
This hardware solves the critical safety challenge of connecting consumer USB ports to noisy, high-voltage industrial RS232 equipment. A 4-layer PCB architecture was necessary to manage power plane routing for both the isolated and non-isolated sides while strictly maintaining safe creepage and clearance distances. Digital isolators were preferred over optocouplers to provide the speed and longevity required for a high-performance, robust field tool.
ESP32 & Custom 3D Enclosure
Automated Testing Equipment (ATE) Rig
- Developed production-line test rig software in C++ on ESP32, capable of automatically diagnosing WS2812 LED bar graph faults and validating correct assembly.
- Engineered a robust system using an internal ESP32 logic with an external hardware Watchdog Timer (WDT), cutting production downtime by 40% due to automated system recovery without human intervention.
Custom FreeCAD 3D-printed mechanical contact fixture paired with automated microcontroller QA firmware for high-throughput factory manufacturing lines. The design of the custom mechanical interface was critical, using pogo pins to provide reliable, non-destructive electrical connections to the Unit Under Test (UUT).
STM32 + ENC28J60 SPI
STM32 Ethernet Environmental Sensor & MQTT Node
- Engineered bare-metal and FreeRTOS-compatible C drivers from scratch to interface an STM32 with a DHT22 precision temperature/humidity sensor using an ultra-low-level, custom bit-banging approach for timing-critical accuracy.
- Integrated an ENC28J60 Ethernet controller via high-speed SPI, implementing non-blocking SPI frame processing to handle concurrent MQTT packet transmission and sensor acquisition without CPU stall.
- Optimized the entire node for low-latency MQTT publication of time-stamped environmental telemetry to an industrial broker, designed for stable 24/7 operation in harsh noise environments where wired connectivity is required.
Built a high-reliability wired industrial monitoring node to provide stable telemetry where Wi-Fi is inadequate. A dedicated STM32 ARM Cortex core is essential to manage the real-time sensor bit-banging, the parallel SPI network traffic, and the MQTT protocol stack simultaneously. The ENC28J60 Ethernet controller, connected over a specialized high-throughput SPI interface, offers a robust and cost-effective wired connectivity solution optimized for low-latency datalogging in demanding environmental scenarios.
Raspberry Pi 3A+ Touchscreen Kiosk
Self-Service Restaurant Kiosk System
- Deployed full-featured Quick Service Restaurant (QSR) application using Flask, SQLite, and Cog kiosk browser on a custom Yocto image.
- Implemented robust RAUC A/B over-the-air update system with automated systemd timers and remote SSH debugging capabilities.
Custom Yocto Linux appliance featuring interactive touch ordering, dynamic upsell recommendation engine (SQLite suggestions model), real-time basket floating UI, automated first-boot GitHub provisioning service, and systemd service orchestration for zero-downtime kiosk boot sequencing.
KiCAD & OrCAD Circuit Design
Arduino Uno PCB & Advanced Custom Clones
- Designed a standard reference Arduino Uno PCB along with an enhanced standalone Arduino clone featuring an integrated I2C EEPROM for non-volatile data storage.
- Engineered a Battery-Powered Arduino Clone equipped with an extended EEPROM IC and an onboard Real-Time Clock (RTC) for precise, low-power time-stamped datalogging.
- Ensured signal integrity routing for serial buses, and generated industrial manufacturing Gerber files following strict DFM and DRC guidelines.
Developed custom schematic captures and multi-layer PCB layouts using KiCAD and OrCAD. The designs feature an ATmega328P core, optimized power supply rail decoupling, precision crystal oscillators, dedicated battery management circuitry, and external I2C EEPROM/RTC modules tailored for standalone and low-power autonomous operations.
Work Experience
Lumel S.A.
Zielona Góra, Poland — Industrial Automation Manufacturer
Electronic Design Engineer
2023 — 2026- Architected firmware and high-reliability PCB hardware designs for commercial industrial automation products and smart grid energy meters deployed across European markets.
- Integrated industrial telemetry communication protocols including MODBUS, Ethernet (SPI), and MQTT across ARM Cortex-M4 microcontroller platforms.
- Led hardware and software verification, debugging signal integrity using logic analyzers, oscilloscopes, and automated test fixtures.
Production Support (Part Time)
2022 — 2023- Optimized factory manufacturing processes and quality assurance routines via automated optical verification and functional testing rigs.
- Validated component redesigns and PCB schematic revisions to prevent production downtime and ensure line yield stability.
Education
University of Zielona Gora — Zielona Gora, Poland
2022 — 2023Master of Engineering, Management and Production Engineering
Graduated under full sponsorship from Lumel S.A.
Thesis: The use of information technologies for knowledge management in small and medium-sized enterprises.
Relevant Academic Coursework & Applied Real-World Skills:
- Metrology in Mechanical & Electrical: Instrument calibration and noise reduction for precision sensor signal acquisition.
- Object-Oriented Programming: Modular, scalable C/C++ architectures for complex firmware and software interfaces.
- Computer-Aided Design & Simulation: 3D CAD modeling of physical hardware housings and mechanical testing rigs.
- Integrated Management & Decision Systems: Industrial workflow automation and factory-floor data logging pipelines.
Medi-Caps University — Indore, India
2016 — 2020Bachelor of Technology, Electrical and Electronics Engineering
Graduated with Honors, specializing in Power Electronics.
Thesis: Observation and control of smart grid using IoT and cloud technology.
Relevant Academic Coursework & Applied Real-World Skills:
- Microprocessors & Microcontrollers: Bare-metal driver development, interrupt management, and low-level register configuration.
- Advanced Power Electronics & Electric Drives: High-efficiency DC-DC converters, motor control switching, and power stage design.
- Electronic Devices & Digital Circuits: Discrete PCB component selection, logic analyzer debugging, and circuit protection.
- Linear Control Systems: Closed-loop feedback controller design (PID) for precise motor speed and power regulation.
Publications
Chapter in Springer Proceedings
"Observation and Control of Smart Grid Using IoT and Cloud Technology"
The traditional electrical grids deals with generation, transmission and distribution have one-way communication and are centered around the distributor. They also lack in routing and interconnection of different types of generations which lead to a reduction in the reliability of supply. Hence to overcome this issue we propose the comprehensive architecture of Smart Grid and it’s Observation and control using the Internet of Things (IoT) and Cloud Technology. We have Integrated the different sources of energy (thermal and renewable) in a system and introduces the automatic routing of electric power according to peak and low demand. It also incorporates the smart metering facility using IoT and Cloud Technology. It can gather, send and receive the real-time data, which provide two-way communication of data of power being consumed at customer’s end to the service producer. The whole data can be stored, accessed and analyzed on the very secured and customized API platform. We have built and thoroughly tested demonstration model of our project having Wi-Fi-based smart meter, which helped us to monitor and control the electric power and to enhance the reliability of the system.